''Ariadna ustulata'' is a species of

tube-dwelling spider Tube-dwelling spiders (Segestriidae) are a family of araneomorph spiders first described by Eugène Simon in 1893. It consists of five genera, two large and widespread, '' Segestria'' and ''Ariadna'', and three smaller genera, '' Citharoceps'', ...

that is endemic to the Seychelles. It has not been recorded on Mahé since 1894, and appears to be restricted to Mont Dauban on

Silhouette Island Silhouette Island lies northwest of Mahé in the Seychelles. It is the third largest granitic island in the Seychelles. It has an area of 20.1 km2 and has a population of 200, mostly workers on the island. The main settlement is La Passe ...

. Its adult population is estimated to be about 7,000 individuals. It is restricted to cloud forests, where it lives in mosses. It is threatened by habitat deterioration from invasive plants, especially '' Cinnamomum verum'', and drying of cloud forests due to climate change.

References

Segestriidae Endemic fauna of Seychelles Critically endangered animals Spiders of Africa Spiders described in 1898 {{Araneomorphae-stub